The on-site test shall strictly abide by the electrical * * operation procedures and take * * measures. The primary and secondary terminals of the test transformer shall come out of the circuit * * and be disconnected from other circuits with obvious disconnection points. To prevent the voltage of the transformer from rising back to other circuits, check the electricity before the test, and then carry out the experiment after installing the grounding wire.

Preventive measures:

1) Check the barrier between primary wiring and operating equipment or other irrelevant equipment.

2) Check whether the fuses of all secondary windings are opened.

3) Check whether the secondary circuit of the current transformer with one and a half wiring methods is untied from other parallel circuits unrelated to the test, and untie it from one side of the test circuit. Avoid directly shorting the secondary circuit, causing other equipment to malfunction.

4) The booster, voltage transformer and high-voltage Lead shall be installed firmly, arranged in places that are not easy to reach, and kept a * * distance from adjacent objects, and then hang signs and install barriers. If high-voltage cables are used as high-voltage leads, insulation tests should be carried out regularly.

5) During the transformer test, the current transformer stops the open circuit and the sensor stops the short circuit.

6) Imprison the wiring of each terminal to prevent the wire from falling.

7) During the experiment, personnel shall be prevented from walking in the experimental area to avoid kicking off the wire.

8) The operating things should have good insulation to avoid touching each other by mistake. The test instruments should be intact and conform to the on-site voltage limit. When testing the voltage loop impedance, the result should be a high resistance value of not less than 20m.

9) The ground wire shall be installed before the on-site error test of the transformer to avoid personal and equipment accidents.

10) The ground wire shall be installed by crimping, and the contact shall be firm and firm.

11) The ground wire shall be installed within the sight range of the experimenter and conform to the installation requirements of the equipment manual.

12) When there is live equipment around the transformer, in order to avoid induced high-voltage electric shock, when connecting the primary line, it is necessary to discharge the ground wire first, and then connect the primary line.

13) All secondary windings of voltage and current transformers shall have one and only one reliable protective grounding.

14) When measuring the error of the transformer under the secondary load, because the secondary circuit of the transformer has been grounded, one end of the calibrator cannot be grounded again.

15) When measuring the insulation, disconnect the tested equipment from all aspects, verify that there is no voltage, and confirm that the equipment is not operated. Prevent others from approaching the tested equipment during measurement.

16) If the polarity indicator of the calibrator acts during the experiment, immediately reduce the voltage regulator to zero, and then disconnect the power supply for inspection.

17) Regulate the polarity mismatch between the transformer and the tested transformer.

18) The specification is different from the transformation ratio of the tested transformer.

19) The specification or the tested circuit is disconnected.